The quantitative determination of analytes in body fluids is of great importance in the diagnoses and maintenance of certain physiological abnormalities. For example, lactate, cholesterol, and bilirubin should be monitored in certain individuals. In particular, determining glucose in body fluids is important to diabetic individuals who must frequently check the glucose level in their body fluids to regulate the glucose intake in their diets. The results of such tests may be used to determine what, if any, insulin and/or other medication needs to be administered. In one type of testing system, test sensors are used to test a fluid such as a sample of blood.
One method of monitoring an individual's blood glucose level is with a portable, hand-held blood glucose testing device (e.g., a meter). To determine the blood glucose level with the meter, a lancet device may be used with a needle lancet that pierces the skin tissue and allows a whole blood sample to form on the skin's surface. Once the requisite amount of blood forms on the skin's surface, the blood sample is transferred to a test sensor. The test sensor is generally placed in an opening in the body of the meter.
Test-sensor cartridges are commonly used to individually dispense test sensors to be used for testing an analyte in a fluid. Test-sensor cartridges may be incorporated directly into, for example, glucose meters to dispense test sensors for use with the meter. The cartridges are used to store multiple sensors and allow users to carry multiple sensors around within a single enclosure. The cartridges also assist in preventing or inhibiting the sensors from being exposed to the environment until they are required for use. A blood or body fluid sample may then be placed on the sensor and analyzed with the meter or similar device to determine the concentration of the analyte being examined.
Each time analyte-testing is performed, a new test sensor is used, and thus, a number of test sensors may be used in a single day. Existing meters are adapted to include, at most, one test-sensor cartridge. This may be undesirable since a user may realize that he or she has used all of the test sensors in the test-sensor cartridge at inopportune times. For example, the user may run out of test sensors while away from home and without having an extra cartridge available, thereby potentially causing substantial inconvenience to the user.
Typically, a meter includes some type of mechanism for indexing and/or excising each test sensor from a cartridge. To index a cartridge, the cartridge may be rotated so that an empty test-sensor cavity may be removed from an excise position and replaced with a test-sensor cavity having a next test sensor therein. The next test sensor may then be excised from the cartridge for use in testing a desired analyte. Indexing and/or excising mechanisms are often complex. For example, the indexing and/or excising mechanism may be motorized. Such a complex indexing and/or excising mechanism may be undesirable since often, many different parts are required, which may increase the cost of manufacturing. Moreover, complex mechanisms may be particularly susceptible to breakage, thus requiring repair or replacement.
It would be desirable to have analyte-testing instruments that assist in addressing one or more of the above disadvantages.